The Viner brothers departed dog-walking startup Wag last year to start a fund focused on consumer startups. The departures came after Josh Viner was replaced as Wag CEO by Hilary Schneider, a former Yahoo executive. Now, the brothers are moving on from the fund and taking a stab at bike-share.

“We started our fund, exclusively with our own capital. Wheels quickly became a massive opportunity, and we’re now entirely focused on this business,” Josh Viner told TechCrunch via email. “We still invest passively when great opportunities present themselves.”

Wheels will join the likes of Uber’s Jump, Lyft’s Motivate and others in competing for bike-share market share. But Wheels says it’s different because of its modular design, which includes swappable parts and batteries. The company says that results in a 4x longer product life cycle compared to other bikes on the market.

“When we evaluated this market, we identified a major opportunity to better serve cities with a sustainability-first approach to dockless electric mobility,” Jonathan Viner said in a press release. “We’ve spent countless research and development hours on new manufacturing and servicing models to afford first-ever offerings such as swappable part replacements and removable batteries.”

But bike-share companies are getting privy to the fact that their unit economics will continue to be trash unless they make some changes. Back in December, JUMP unveiled its next generation of bikes with swappable batteries and on-board diagnostics.

Already, Wheels says it has surpassed competitors in daily trips in San Diego’s Gaslamp district. Wheels also says it sees more than seven rides per day, per bike. In the near-term, Wheels has plans to deploy its bikes “rapidly” throughout Southern California, while working with city officials.

Wheels has also brought on a handful of former Bird, Uber and Lyft executives. That includes Ben Shaken, former Director of Product at Lyft, and Marco McCottry, formerly of Uber and Bird.

“I’ve seen the explosion of last mile transportation first hand and understand the importance of keeping a promise of sustainability to consumers and society,” McCottry said in a press release. “And that’s why I’m so excited to be a part of Wheels. The solutions to so many issues experienced by the first wave are baked into the operational approach.”